Motion sensor in sporting equipment

ABSTRACT

Sports equipment includes an embedded optical sensor. The embedded optical sensor includes an image array and a navigation engine. The navigation engine receives image information originating from the image array and performs a correlation on the image information to calculate overlap of images and to determine shift between images in order to detect motion.

BACKGROUND

In many sports, various types of equipment are used. This equipment can be categorized into three wide classes. The first class of equipment includes equipment that serves as a marker or symbol of possession. Typical examples of such markers of possession include balls or disks.

The second class of equipment includes extensions to the athlete. Typical examples of such extensions of the athlete include a club, a bat or a racket. The success a person achieves as an athlete is often determined by skillful use of extensions and by controlling skillful interactions between an extension and a marker or symbol of possession.

The third class of sports equipment is equipment that monitors sports activity. This includes equipment such as speedometers, pedometers, stopwatches and so on.

For example, in the game of golf, a golfer holds a golf club, and swings the golf club through impact striking a golf ball and causing the golf ball to move in an intended direction. When the golf ball is far away from the intended hole destination, for example when a golfer is striking the golf ball from a teeing area, it is often desirable for the golfer to strike the golf ball with a golf club with a sufficient force to impart substantial velocity to the golf ball while still as accurately as possible controlling the direction and distance the golf ball ultimately travels. Several factors, including golf club speed at impact, the location of the clubface that comes into contact with the golf ball, and the orientation of the clubface with respect to the target at impact, have a significant effect in determining the final resting place of the golf ball. The ability to monitor these factors is important feedback in training a golfer to strike the golf ball with efficiency and accuracy and in evaluating golf equipment.

Golf balls are dimpled, but not solely for aesthetic reasons. Golf balls are dimpled primarily for the purpose of imparting desirable aerodynamic qualities to the flight of the golf ball. For example, appropriately placed dimples allow a golf ball to fly an optimal distance for a given initial velocity. The addition of spin to the golf ball, imparted to the golf ball at impact by the golf club, interacts with aerodynamic forces and affects the height, the distance and the direction of flight of the golf ball. The ability to impart a desired spin to a golf ball is a very important ability to those highly skilled in the game of golf.

When a highly skilled golfer practices, the golfer often watches the flight of the golf ball for clues as to impact conditions of the golf club with the golf ball. In addition, for the very devoted analyst of golf equipment and golf swing mechanics, additional monitoring tools can be used, such as high-speed video, speed guns, digital cameras, high-speed strobes, and image analysis equipment. Properly used, these tools can provide additional information about impact and launch conditions of the golf ball.

Golf is not the only sport where spin imparted to a ball is important. In fact, for any sport that involves projectiles traveling through air, control of spin rate and direction of travel are very important factors in success in competition. For example, in baseball, highly skilled pitchers of baseballs are able to impart a specific type of spin to the baseball. The interaction of the spin of the baseball with the non-uniform surface of the baseball and air currents cause the baseball's trajectory to vary as it moves from the pitcher hand towards the vicinity of a baseball batter. The ability to throw a baseball that has various curved trajectories is possible by controlling the spin on a baseball. Feedback on the actual spin placed on a baseball at a pitching release point can thus be very helpful feedback to a pitcher. Similarly, launch information for footballs, Frisbee flying disks, and other similar sporting equipment can be very useful in the design, evaluation and use of sporting equipment.

SUMMARY OF THE DISCLOSURE

In accordance with an embodiment of the present invention, sports equipment includes an embedded optical sensor. The embedded optical sensor includes an image array and a navigation engine. The navigation engine receives image information originating from the image array and performs a correlation on the image information to calculate overlap of images and to determine shift between images in order to detect motion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows optical motion sensors embedded in a ball in accordance with an embodiment of the present invention.

FIG. 2 shows a simplified block diagram of an optical motion sensor in accordance with an embodiment of the present invention.

FIG. 3 shows a simplified block diagram of multiple optical motion sensors in accordance with another embodiment of the present invention.

FIG. 4 illustrates optical motion sensors embedded in a baseball bat in accordance with an embodiment of the present invention.

FIG. 5 illustrates an optical motion sensor embedded in the head of a golf club in accordance with an embodiment of the present invention.

FIG. 6 illustrates optical motion sensors embedded in a football and in a flying disk, such as a Frisbee flying disk, in accordance with an embodiment of the present invention.

FIG. 7 illustrates a training station used to obtain and analyze information from optical motion sensors embedded in sports equipment in accordance with an embodiment of the present invention.

FIG. 8 shows optical motion sensors embedded in a strap to form sports equipment for monitoring activity of a performer in accordance with an embodiment of the present invention.

DESCRIPTION OF THE EMBODIMENT

FIG. 1 shows an optical motion sensor 11, an optical motion sensor 12 and an optical motion sensor 13 embedded in a ball 10. For example, ball 10 is sports equipment, such as a baseball, a golf ball or another ball used when playing a game or sport. Optical motion sensors 11, 12 and 13 are embedded in locations of ball 10 such that they point in orthogonal directions. This allows detection and monitoring of the direction of travel and spin of ball 10. If less complete information is desired, fewer optical motion sensors can be utilized. The use of additional optical motion sensors can be used if redundant information is desired.

FIG. 2 is a block diagram of an optical motion sensor. An image array 21 is implemented, for example, using a 32 by 32 array of photodetectors. Alternatively, other array sizes can be used, dependent upon the image resolution necessary to give sufficient information for a particular application. An analog-to-digital converter (ADC) 22 receives analog signals from image array 21 and converts the signals to digital data.

An automatic gain control (AGC) 23 evaluates digital data received from ADC 22 and controls shutter speed and gain adjust within image array 21. This is done, for example, to prevent saturation or underexposure of images captured by image array 21.

A navigation engine 24 evaluates the digital data from ADC 22 and performs a correlation to calculate overlap of images and to determine shift between images in order to detect motion. For example, the correlation is performed using an image processing algorithm such as a convolution, or can be performed in another way to detect image shift. Navigation engine 24 determines a delta x value placed on an output 25 and determines a delta y value placed on an output 26. Image array 21, ADC 22 and navigation engine 24 together form a tracking device that tracks motion of ball 10.

A controller 28 receives the delta x value placed on output 25 and the delta y value placed on an output 26. Controller 28, through a transceiver 29, forwards representatives of these values to a host system. The representatives of the delta x values placed on output 25 and the delta y values placed on an output 26 can be transmitted immediately and continuously to the host system, or, alternatively, can be stored for later transmission in response to a query from the host system.

In general, it is noted that only fairly rudimentary images are required for many applications. For example, an optical motion sensor located on the equator of a spinning golf ball, would typically see an alternative pattern of “sky” and “land”. The frequency of this detected pattern is indicative of the rotational velocity of the golf ball. For this reason, dependent upon a particular implementation and application, sophisticated imaging capability is often not required to obtain the desired information.

For example, optical motion sensor technology within existing optical mice can be directly adapted to implement image array 21, ADC 22, AGC 23 and navigation engine 24. For further information on how this standard functionality or similar functionality of optical mice are implemented, see, for example, U.S. Pat. No. 5,644,139, U.S. Pat. No. 5,578,813, U.S. Pat. No. 5,786,804 and/or U.S. Pat. No. 6,281,212 B1.

While in FIG. 2 each optical motion sensor is completely self-contained, when implementing more than one optical motion sensor in a single piece of sporting equipment, some functionality can be shared between optical motion sensors.

For example, FIG. 3 is a block diagram of the implementation of three optical motion sensors. For a first optical motion sensor, an image array 31 is implemented, for example, using a 32 by 32 array of photodetectors. Alternatively, other array sizes can be used, dependent upon the image resolution necessary to give sufficient information for a particular application. An analog-to-digital converter (ADC) 32 receives analog signals from image array 31 and converts the signals to digital data.

An automatic gain control (AGC) 33 evaluates digital data received from ADC 32 and controls shutter speed and gain adjust within image array 31. This is done, for example, to prevent saturation or underexposure of images captured by image array 31.

A navigation engine 34 evaluates the digital data from ADC 32 and performs a correlation to calculate overlap of images and to determine shift between images in order to detect motion. Navigation engine 34 determines a delta x value and a delta y value that are placed on a communication path 35.

For a second optical motion sensor, an image array 41 is implemented, for example, using a 32 by 32 array of photodetectors. Alternatively, other array sizes can be used, dependent upon the image resolution necessary to give sufficient information for a particular application. An analog-to-digital converter (ADC) 42 receives analog signals from image array 41 and converts the signals to digital data.

An automatic gain control (AGC) 43 evaluates digital data received from ADC 42 and controls shutter speed and gain adjust within image array 41. This is done, for example, to prevent saturation or underexposure of images captured by image array 41.

A navigation engine 44 evaluates the digital data from ADC 42 and performs a correlation to calculate overlap of images and to determine shift between images in order to detect motion. Navigation engine 44 determines a delta x value and a delta y value that are placed on a communication path 45.

For a third optical motion sensor, an image array 51 is implemented, for example, using a 32 by 32 array of photodetectors. Alternatively, other array sizes can be used, dependent upon the image resolution necessary to give sufficient information for a particular application. An analog-to-digital converter (ADC) 52 receives analog signals from image array 51 and converts the signals to digital data.

An automatic gain control (AGC) 53 evaluates digital data received from ADC 52 and controls shutter speed and gain adjust within image array 51. This is done, for example, to prevent saturation or underexposure of images captured by image array 51.

A navigation engine 54 evaluates the digital data from ADC 52 and performs a correlation to calculate overlap of images and to determine shift between images in order to detect motion. Navigation engine 54 determines a delta x value and a delta y value that are placed on a communication path 55.

A controller 38 receives the delta x values and delta y values placed on communication data path 35, communication data path 45 and communication data path 55. For example, communication data paths 35, 45 and 55 are implemented using wires within the sporting equipment in which the optical motion sensors are embedded. Alternatively, communication data paths 35, 45 and 55 are implemented using wireless technology. Controller 38, through a transceiver 39, forwards representatives of these values to a host system. The representatives of the delta x values and delta y values for each optical motion sensor can be transmitted immediately and continuously, or, alternatively, can be stored for later transmission in response to a query from a host computer system.

While FIG. 1 shows optical motion sensors embedded in a ball, optical motion sensors can also be used in other types of sporting equipment.

For example, FIG. 4 shows an optical motion sensor 61, an optical motion sensor 62 and an optical motion sensor 63 embedded in a bat 60. For example, bat 60 is a type of bat used in baseball. Optical motion sensors 61, 62 and 63 are embedded in locations of bat 60 such that they point in orthogonal directions. This allows detection and monitoring of the direction of travel and spin of bat 60. If less complete information is desired, fewer optical motion sensors can be utilized. The use of additional optical motion sensors can be used if redundant information is desired.

For example, FIG. 5 shows an optical motion sensor 71, embedded in the bottom of a golf club head 70. The single optimal motion sensor allows detection and monitoring of swing speed of club head 70. If more complete information is desired, more optical motion sensors can be utilized. Similarly, optical motion sensors can be embedded in other types of bats, sports rackets, paddles, and so on.

FIG. 6 shows an optical motion sensor 91, and an optical sensor 92 embedded in a football 93. FIG. 6 shows an optical motion sensor 97, and an optical sensor 98 embedded in a flying disk 95. Football 93 and flying disk 95 are meant to be exemplary of the many types of balls and other sports equipment in which can be embedded optical monitors.

Optical motion sensors can be embodied in other types of sporting equipment. For example, optical motion sensors can be mounted in a billiard ball and/or pool stick to detect quality of contact and/or characteristics of roll (such as spin or “English”). Optical motion sensors can also be mounted in wheels, such as for example, a bicycle wheel, a skateboard wheel or a wheel of an inline skate, to detect characteristics of motion, such as speed of wheel surface. In the case of wheels, the embedded optical motion sensors allow absolute measurement of speed without the need to exactly know tire circumference in order to translate rotational velocity to linear velocity.

FIG. 7 illustrates a training station used to obtain and analyze information from optical motion detectors embedded in sports equipment. For example optical motion sensors are embedded in a ball 81 and or a club 82. The optical sensors gather information as a player 80 performs a golf swing. For example, if appropriately placed and oriented on ball 81 and club 82, optical motion sensors can capture the quality of impact between club 82 and ball 81. Optical motion sensors can be located and oriented so as to observe quality of impact, including the actual speed at impact, location on the club at which impact occurs, the speed of club 82 immediately before impact, the speed of ball 81 relative to club 82 immediately after impact, the orientation of the club face with respect to ball 81 before, during and after impact, and so on.

A host system 83 located, for example, on a nearby support 84, gathers and analyzes information from the optical sensors. For example, host system 83 is a lap top computer or a personal digital assistant (PDA) with wireless communication capability.

Sports equipment can also be used to directly monitor motion of a performer. For example, FIG. 8 shows a strap 100 with an embedded optical sensor 101, an embedded optical sensor 102 and an embedded optical sensor 103. Strap 100 is designed to attach optical sensors directly to a performer to monitor activity of the performer. For example, strap 100 can be sized to attach to a performer at the waist, ankle, leg, arm wrist, forehead, chest, neck, or etc. Multiple straps can be used if additional feedback is desired. Similarly, optical sensors can be embedded within the uniform or other clothing or jewelry of the performer, and thus directly attached to the performer for the purpose of obtaining feedback pertaining to motion of the performer.

For example, various optical sensors can be attached to a performer, for example, a gymnast, a skater, a runner, a diver, a dancer, an actor, a speaker, a singer or other type of performer to track motion of one or more body parts during training or performance. The performer can be a human, but can also be another type of animal for example, a horse in training for an equestrian event or a dog in training for a race or show.

In addition to giving performance feedback, the optical sensors can be used for other purposes. For example, the optical sensors can be attached to an alert system to provide immediate feedback and/or warnings to a performer. For example, the feedback could indicate, that an equestrian is not traveling at a sufficient speed to clear a steeple, a long jumper is not traveling at an optimal speed to maximize jump distance, or a shot putter is not rotating at an optimal rotational speed to maximize throwing distance,

The foregoing discussion discloses and describes merely exemplary methods and embodiments of the present invention. As will be understood by those familiar with the art, the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. Accordingly, the disclosure of the present invention is intended to be illustrative, but not limiting, of the scope of the invention, which is set forth in the following claims. 

1. Sports equipment, comprising: an optical sensor embedded within the sports equipment, the optical sensor including: an image array, and a navigation engine that receives image information originating from the image array and performs a correlation on the image information to calculate overlap of images and to determine shift between images in order to detect motion.
 2. Sports equipment as in claim 1 wherein the sports equipment includes: at least one additional optical sensor embedded within the sports equipment.
 3. Sports equipment as in claim 1 wherein the sports equipment is a substantially round ball that includes: two additional optical sensors embedded within the sports equipment and each optical sensor embedded with the sport equipments facing in a direction orthogonal to other optical sensors embedded in the sports equipment.
 4. Sports equipment as in claim 1 wherein the sports equipment is one of the following: a golf ball; a baseball; a football; a flying disk; a billiard ball.
 5. Sports equipment as in claim 1 wherein the sports equipment is one of the following: a golf club; a baseball bat; a bicycle wheel; a wheel of an inline skate; a wheel of a skateboard; a pool cue.
 6. Sports equipment as in claim 1 wherein the optical sensor additionally comprises: an analog-to-digital converter that receives analog signals from the image array and converts the signals to digital data; and, an automatic gain control that evaluates digital data received from the analog-to-digital converter and controls shutter speed and gain adjust within the image array.
 7. Sports equipment as in claim 1 wherein the optical sensor additionally comprises: a controller that receives motion detection information from the navigation engine and forwards representatives of the motion detection information from the navigation engine to a host system.
 8. Sports equipment as in claim 1 wherein the sports equipment additionally comprises: at least one additional optical sensor embedded within the sports equipment; and, a controller that receives motion detection information from the optical sensor and the at least one additional optical sensor and forwards representatives of the motion detection information to a host system.
 9. Sports equipment as in claim 1 wherein the sports equipment attaches directly to a performer to monitor movement of the performer.
 10. A method for obtaining motion information from sports equipment, the method comprising: embedding an optical sensor embedded within the sports equipment, the optical sensor including an image array, and a navigation engine that receives image information originating from the image array and performs a correlation on the image information to calculate overlap of images and to determine shift between images in order to detect motion; and, gathering and evaluating information from the embedded optical sensor.
 11. A method as in claim 10 additionally comprising the following: embedding at least one additional optical sensor embedded within the sports equipment; and, gathering and evaluating information from the at least one additional embedded optical sensor.
 12. A method as in claim 10 additionally comprising the following: embedding two additional optical sensor embedded within the sports equipment so that each optical sensor embedded in the sports equipment faces in a direction orthogonal to other optical sensors embedded in the sports equipment.
 13. A method as in claim 10 wherein the correlation on the image information is performed using convolution.
 14. Sports equipment, comprising: means for optically sensing motion embedded within the sports equipment, the means for optically sensing motion including: means for producing image information, and means for receiving the image information and performing a correlation on the image information to calculate overlap of images and to determine shift between images in order to detect motion.
 15. Sports equipment as in claim 14 wherein the sports equipment includes: at least one additional means for optically sensing motion embedded within the sports equipment.
 16. Sports equipment as in claim 14 wherein the sports equipment is a substantially round ball that includes: two additional means for optically sensing motion embedded within the sports equipment and each means for optically sensing motion embedded in the sports equipment facing in a direction orthogonal to other means for optically sensing motion embedded in the sports equipment.
 17. Sports equipment as in claim 14 wherein the sports equipment is one of the following: a golf ball; a baseball; a football; a flying disk.
 18. Sports equipment as in claim 14 wherein the sports equipment is one of the following: a golf club; a baseball bat.
 19. Sports equipment as in claim 14 wherein the sports equipment attaches directly to a performer to monitor movement of the performer.
 20. Sports equipment as in claim 14 wherein the sports equipment additionally comprises: at least one additional means for optically sensing motion embedded within the sports equipment; and, means for receiving motion detection information from the means for optically sensing motion and the at least one additional means for optically sensing motion and forwarding representatives of the motion detection information to a host system. 